While driving north on South Union St. and crossing the railroad tracks just before Merrimack St., had a chance to look up at the south side (sunny) of the 200 Merrimack St. building. It was a pleasant surprise to observe one of the adult Peregrines perched on a protruding short steel beam. This has been one of many perches around the building. It launched into flight and landed on one of the nearby rooftop peaks. Later it flew off to the west and perched on one of the round silver posts in the NSTAR facility just down the street.